Array Sequences

Array sequences are mutable sequences of fixed size which store their
elements internally in an Array[Object]. They are implemented in
Scala by class ArraySeq.

You would typically use an ArraySeq if you want an array for its
performance characteristics, but you also want to create generic
instances of the sequence where you do not know the type of the
elements and you do not have a ClassManifest to provide it at
run-time. These issues are explained in the section on arrays.